Engine control device with an induction pressure reset mechanism responsive to operation of an antidetonant fluid injection system



Jan- 25, 954 A. w. BLANCHARD ENGINE CONTROL DEVIC E WITH AN INDUCTION PRESSUR RESET MECHANISM RESPONSIVE TO OPERATION `OF AN ANTIDETONANT FLUID INJECTION SYSTEM 2 Sheets-Sheet l` Filed May 14, 1949 i Mfr/mq N NNW www O. @n

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Jan 26, l954 w. BLANCHARD 2,667,148

ENGINE CONTROL DEVICE WITH AN INDUCTION PRESSURE RESET MECHANISM RESPONSIVE TO OPERATION OF' AN ANTIDETONANT FLUID INJECTION SYSTEM Filed May 14, 1949 2 sheets-sheet 2 lNcnEAsl-I Cf?? PRESSURE .nf

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ALLE/V WBL/VCHAR Patented Jan. 26, 1954 ENGINE lCONTROL DEVICE WITH AN INDUC- TION PRESSURE RESET MECHANISM RE- SPONSIVE T OPERATION OF AN ANTI- DETONANT FLUID INJECTION SYSTEM Allen W. Blanchard, Allendale, N. J., assignor to Bendix Aviation Corporation, Teterboro, N. J., a corporation of Delaware Application May 14, 1949, Serial No. 93,215

7 Claims. (Cl. 12S- 25) l The present invention relates to improvements in control systems and apparatus for the power units of aircraft of the type disclosed and claimed in the copending application Serial No. 561,083

`nled October 30, 1944, by Joel D. Peterson.

With present aircraft supercharged engines the best performance is maintained only by adjustment of the various functions of the engine to values consistent with efficient and safe operation of the engine, with proper compensation for external factors such as the atmospheric pressure surrounding the aircraft, which pressure is directly affected by changes in the altitude of the aircraft. The functions of the power unit controlled are engine manifold pressure and engine speed. The manifold pressure is regulated through control of an induction throttle valve and the driving speed of the supercharger, while the engine speed is regulated usually by varying the pitch of the aircraft propeller through a propeller pitch governor control.

During the operation of .so-called water or "anti-knock iiuid injection systems for suppressing predetonation in internal combustion engines, an increase in the air inlet pressure of the induction system for the engine is permissible and desirable in order that greater engine power may be obtained than :hen such injection system is not in operation. Therefore an object of the invention is to provide a novel electrically controlled solenoid to limit the manifold pressure to a safe dry range during non-operation of the fluid injection system while permitting higher manifold pressure settings by opera-tion of the control lever during operation of the anti-knock fluid injection system. The electrically controlled solenoid is operated in conjunction with the water injection control system,

The above and other objects and features of the invention will appear more fully hereinafter from a consideration of the following description taken in connection with the accompanying' drawings wherein several embodiments of the invention are illustrated by way of example.

Figure l is a diagrammatic illustration of the control system disclosed and claimed in the said copending application Serial No. 561,083.

Figure 2 is a diagrammatic view illustrating the novel pressure reset mechanism.

Figure 3 is a diagrammatic View illustrating the novel throttle valve position follow-up for the waste gate.

Figure 4 is a. diagrammatic view illustrating the novel multi-engine control.

Figure 5 is a perspective view of a modified form of the control.

In order that the improvements forming the subject matter of the present application may be better understood, the electric control system shown in Figure 1 and heretofore disclosed and claimed in the said copending application Serial No. 561,083 'led by Joel D. Peterson will be first explained.

Referring in detail to the electric control system of Figure 1, there is provided a single lever and a compound clutch 2, whereby an induction throttle valve of an aircraft engine may be selectively connected either to an automatic control system or directly to the control lever I for manual operation.

The clutch 2 may be of a type such as shown in detail in the said copending application Serial No. 561,083, and includes an electromagnet which when energized operatively connects the arms 28 and 30, as shown in Figure 1.

The arm 28 is operably connected through a rod 3S to the automatic control mechanism, while the arm 30 is connected through a rod l0 to the throttle control valve. Thus upon energization of the electromagnet of the clutch 2, the throttle control valve is operably connected to the control system through the arms 28 and 30.

When the electromagnet 20 is cle-energized, a spring biases the clutch so as to disconnect the arm 28 from driving relation with the arm 30 while drivingly connecting the arms 49 and 30. As previously explained, the arm 30 is connected through rod 40 to the induction throttle valve as shown in detail in the aforenoted application Serial No. 561,083.

Thus when the clutch 2 is cie-energized, the automatic electrical control system is inoperative and the induction throttle valve may be manually adjusted through operation of the pilots control lever I. A double pole switch St is provided to energize or de-energize the automatic control system simultaneously with the electromagnet 20 through electrical conductors 6l, 62, 63 and 64 so that the induction throttle valve may be automatically or manually controlled as desired. Moreover, it will be readily seen that as a safety provision upon a power failure the system will be automatically transferred by the de-energization of the electromagnet of the clutch 2 to manual operation.

The pilots throttle control lever l is further suitably connected so as to effect selective electrical control of the automatic electrical control system. Thus the lever l is connected by an actuator rod 'IG to an arm 1l, which is operably connected through a shaft T2, a gear train "i3, and shaft 'I4 to rotor T1 of an electrical induction type transmitter or transformer 16.

The transmitter 'I6 as illustrated hereinafter, comprises the rotor winding 'I1 which may be angularly displaced in relation to stator windings '18, 'I9 and 80 by the control lever I, and the rotor winding I'I is arranged in `inductive relation with the stator windings. Voltages are applied to the rotor winding I1 through electrical conductors TIA and 'I'IB connected to conductors 63 and 64 leading from a suitable source of alternating current. Angular displacement of the transmitter rotor winding TI causes the voltage applied to the rotor winding 'Il to induce varying voltages in the stator windings "I8, 'I8 and Si? of the transmitter 'Iii depending upon the relative position of the rotor winding TI. The voltages thus induced in the stator windings of the transmitter are applied through conductors 85, 86 and 8l to the stator windings Si), 9i and '92 of the propeller pitch governor actuator followup transformer or receiver 93.

PROPELLER FETCH GOVERNOR CONTROL Rotatably mounted within the stator windings 80, 9i and 92 and in inductive relation therewith, is a rotor winding 94. f the winding 94 is not in a position in relation to the stator windings G, 9i and 92 corresponding to a position at right angles to the induced field or the relative position of the rotor winding T! to the stator windings i8, iii and Sii there will be induced into the rotor winding Q4 a voltage. The rotor winding Qd is connected through electrical conductors I8@ and Ii to the input of an amplifier II. The voltage induced into the winding 94 will cause an alternating current to flow to the amplifier H0, which is in phase or in phase opposition with the alternating current flow supplied through the conductors 63 and 6d, depending upon the direction of the difference in the position of the rotors 'I7 and 94.

The amplifier H may be of any suitable type of torque amplifier well known in the art, or may be an amp-liner of a type such as shown, for example in the expired Patent No. 1,586,233, dated May 25, 1926, and granted to H. Anschutz- Kaempfe. Electrical conductors III and H2 lead from the output of the amplifier H3 to a secondary or auxiliary winding H3 of a twophase motor lili. A main winding H is connected through electrical conductors HSA and iIB which are connected to conductors 63 and 64 leading to the same alternating current source as the transmitter motor winding 1l.

Thus if the rotor windings I'I and 94 are set in such a manner in relation to the stator windings that no voltage is induced into the winding 94 no current will flow in the auxiliary motor winding H3 of the two-phase motor H4 for there would be no alternating current flowing in the input circuit and II of the amplifying unit II. The motor H4 will therefore not operate for there is no rotating eld.

When the rotor windings 'II and 94 are positioned at different angular relations to the stator windings from the null position, a voltage will be impressed on the winding 9i., that is to say on the input circuit IDG and IGI of the amplier IIS, and the said voltage will be in phase or in phase opposition with the voltage supplied through the conductors 63 and 6G.

The amplified current which iiows in the auxiliary winding H3, will thus produce a corresponding field. Provision is further made in the amplifier IIB, in a manner for example such as shown in the patent previously noted to H. Anschutz-Kaempfe, whereby the said auxiliary current or auxiliary field will have a phase displacement or difference of degrees relative to the main current or main eld, so that said fields form together a rotating field of sufficient magnitude to start the motor II4. It will depend on the phase direction of the alternating current voltage at the input of the amplifier IIIJ whether the auxiliary eld will be displaced 90 degrees relative to the main field in the forward or backward direction or in other words, the direction or rotation of the rotating eld will depend upon the direction of angular variation of the rotor winding TI and 94.

The motor II 4 is so arranged that if the receiver rotor 94 is not in a position corresponding to the null position for that of the transmitter rotor 'I1 an electrical signal is applied to the amplifier I I0 which will feed power to the motor II4 to cause rotation of the receiver rotor 94 through a shaft II4A and interconnecting mechanical means, as will be explained, so as to bring the receiver rotor 94 to a position corresponding to the null position for the position of the transmitter rotor l?, whereupon the signal of the input circuit of the amplifier III) will cease and rotation of the motor H4 terminate.

The rotor of the motor I I4 is connected by the shaft I I4A through a suitable gear train I I6 and shaft III to an arm H8 to which is connected a rod IIS leading to a suitable propeller pitch governor control.

The rotor winding 94 follows up or measures for each corresponding change of position of the transmitter, the setting of the propeller pitch governor. The governor is actuated by the follow-up motor H4, and its ratio of movement is controlled by reduction gear train IIB and a cam I3I, to thereby position the follow-up rotor winding 94 of the receiver 33 shown in Figure l, so as to maintain proper relationship between the engine speed and manifold pressure, as will be explained. To provide for this ratio of performance there is provided a rotor shaft I32 on which is mounted a follower I33 which may be biased under suitable spring means not shown, into contacting relation with the cam surface of cam I3I. The follower I33 is arranged to position the receiver rotor winding 94 through the motor II4 and cam I3I according to the movement of the pilots control lever I, until the position of the rotor 94 agrees with that of the transmitter rotor TI.

The cam I3I provides a non-lineal continuous smooth curve of actuation for the governor, not shown, and which co-acts with the selected position of the transmitter i6 to maintain proper speed relationships of the engine to those selected 'by the pilot.

Thus, as in the other follow-up motor arrangements of the several actuators hereinafter to be described, the rotor two-phase motor H4 in the governor actuator is energized and angularly positioned accordingly to a selected position of the master transmitter 'I6 to thereby actuate rod H9 through lever H8 mounted on cam shaft II'I, until rotor 94 of the governor follow-up transformer 93 is angularly shifted to a null position for no voltage output to amplifier I.

The rod H9 is connected to a propeller pitch governor control which may be of any suitable type well known in the art, or may be of a type shown in the said copending application Serial No. 561.083.

THROTTLE ACTUATOR In addition to operating the propeller pitch governor control the positioning of the rotor 11 also controls the position of the induction throttle valve which regulates the induction pressure of the engine as will be explained.

As shown in Figure 1, there is provided a second receiver 200 which has a rotor winding and stator windings 202, 203 and 204. The stator winding 202 is connected through electrical conductors 81A and 81 to the stator winding 80 of the transmitter 16, while the stator winding 203 is connected through electrical conductors 85A and 86 to the stator winding 10 of the transmitter 16. A high impedance inductive winding 205 is provided in the conductor 86A and the winding 205 forms one stator winding of an induction switch 206.

The induction switch 206 has a second inductive stator winding 201 which is preferably positioned at right angles to the inductive winding 205 so that when a rotor winding 208 of the induction switch 206 is positioned at right angles to the winding 201, as shown in Figure 1, the winding 208 will be inductively coupled with the winding 205 and there will be no inductive coupling between the winding 208 and winding 201. However, when the rotor Winding 208 is positioned at right angles to the winding 205 the winding 208 will be inductively coupled to the winding 201 and there will be no inductive coupling between the Winding 208 and the winding 205.

The rotor Winding 208 is connected by electrical conductors 2|0 and 2|| to the input of an amplifier 2|5 of similar type to the amplifier ||0 previously described. The amplifier 2|5 has output conductors 2|6 and 2|1 in which is inserted one of the two windings of two-phase motor 220 and which winding will be hereinafter described as secondary winding 22|. The main winding 222 ls connected through electrical conductors 224 and 225 to the alternating current conducted through conductors 63 and 64. The rotor winding 20| of the receiver 200 is connected through electrical conductors 230 and 23| with said source of alternating current and is rotatably positioned in relation to said stator windings 202, 203 and 204 by said motor 220, as will be explained.

As shown in Figure 1, the stator windings 19 and 80 of the transmitter 16 together with the electrical conductors 86, 81, 86A, 81A, stator winding 205 of induction switch 206 and stator windings 202 and 203 of the receiver 200 provide a closed circuit.

There is induced in this closed circuit through the alternating current iiowing in the rotor winding 11 a `first voltage and through the alternating current flowing in the winding 20| a second voltage which tends to oppose the first voltage. If the rotor winding 11 be positioned at a diierent angular relation to the stator windings 18 and 80 and the rotor winding 20| is positioned in relation to the stator windings 202 and 203, it will be readily seen that a greater or less voltage will be induced in the closed circuit by the one than by the other. The diierence between these induced voltages will effect a current flow through the high impedance windings 205.

IIhus in the event the rotor inductive winding 208 of the switch 205 is positioned in inductive relation to the stator winding 205 la corresponding voltage will be induced in the Winding 208, which upon amplification by the amplifier 2|5 will cause an alternating current flow in the auxiliary winding 22| `of the two-phase motor 220; such current iiow will have a phase displacement or dilerence of ninety degreesrelativeV to the main winding 222, so as to effect rotation of the motor 220. The direction of rotation of the rotating field will depend upon whether the voltage induced into the closed circuit by one or the other of the rotor windings 11 or 20| be greater; the motor 220 being so arranged as to move the rotor winding 20| in a direction relative to the stator windings 202 and 203 so as to cause the voltages induced into the said circuit to equalize, whereupon no current will ow in the winding 205 and rotation of the motor 220 will terminate. The motor 220 drives the rotor winding 20| through a suitable driving means including shaft and reduction gearing 240. The motor 220 also drives through shaft 242, gear train 244, shaft 248 and arm 245, the rod 39 and arm 28 of the electromagnetically operated clutch 2. The motor 220 upon energization of electromagnet of clutch 2 controls the position of the induction throttle valve. The motor 220 also drives through shaft 248, a cam 250.

An arm 25| rides in contacting relation along` the cam surface of the cam 250 under suitable biasing means, such as a spring tension means, not shown. The arm 25| is drivingly connected through a shaft 253, suitable gear train 254, and shaft 255 to the rotor 208 of the induction switch 206 so that upon rotation of cam 250 to a position Where the arm 25| rides on raised portions of the cam 250, the rotor 208 will be shifted to a position at right angles to the winding 205 and in inductive relation to winding 201.

It will be readily seen, that with the rotor 208 of the induction switch 206 positioned in relation to the inductive winding 205, the motor 220 effects a follow-up of the position of the transmitter rotor 11. Thus movement of the rotor 11, in a counter-clockwise direction, will eiect a corresponding follow-up clockwise movement of the winding 20| and counter-clockwise movement of the cam 250 until a shifting of the induction switch rotor winding 208 in response to movement of the control lever is effected so as to place the winding 208 in non-inductive relation with the winding 205 and in inductive relation with the winding 201. Such counter-clockwise movement of the cam 250 will of course eiect a corresponding counter-clockwise movement Of the arm 245 affixed to the shaft 248 so as to progressively open the throttle valve through rod 39, arm 28, clutch 2, arm 30 and rod 40.

The cam 250 is so arranged that the direct motion follow-up of the rotor 11 is eiected for a predetermined range of movement of the throttle valve, such as, for example from full closed position to thirty per cent open throttle position. At the latter predetermined position, the cam 250 will begin shifting the induction switch rotor winding 208 to a position out of inductive relation with winding 205 and into inductive relation with winding 201. The action may take place for a predetermined range of movement of the throttle valve, for example from thirty per cent to thirty-five per cent open position of the throttle valve.

a position in inductive relation with the windingv The. manifold pressure follow-up.v arrangement for maintaining the/engine manifold*` pressure in accordance, with the pilotsselectedV pressure comprises a two-celled! evacuatedl bellows 265-; a. take-off` rodi 2&3',` and a bellows seal:y 261 for sealing-fthesliaft opening in the. casing: 268t The rod? 26552-15,V connectedby# arrn-y 210 andsha-ft 2631 to the* single phase` rotor 21| of)4 the receiver transformer 251i.l The. casingI 268i is= sealed; and.-

connects to the intake manifold of eng-ine-A 4' by conduit 288: g

'LhusL when the evacuated diaphragm Zi collapses; as; the pressure at the-V intake manifoldincreasesA aresulting pull: is exerted on rod 266', therebymovingrotor winding 2-'!-|-.- Now; ifthe pressure selected by control-leverconnected-to transmitter 'I3 is different from the then existing engine manifold pressure, there is a voltageinduced-inthe rotor 211|# due to its angular relationship tothe resultant field produced in the '1 stator windings 23B-, 26| and 252. AccordinglyI iii-the position of the rotor which is determined bythe engine-manifold pressure in relationA to the stator-windings 258, Ztl-and 252 `corresponds to the nul-l posi-tion, there will be no voltage induced in the rotor- 21|; However, if the-` rotor windings 2.-| is-not at--a null position relative-totheposition ofthe rotor winding l-la voltage will-be-induced-inthe rotor 271|-, the phase of which isdetermined-by the direction of the difference in the relative positions' ofv thel rotor winding '|1-- and 2H'. The voltage so induced-in the rotor 2'|-'!- is-applied through conductor 282- and `283 tothe stator winding-201, this induces a corresponding voltage in the rotor winding- 208 ofthe inductive switch 20S-causinga iiow-I of alterna-tingA current through conductors 2 IIJ-'and'.i I to the input offthe'amplier 215il As previously explained, output conductors 2|i and 2|"|- lead from the amplifier 2|5' to the seci,

ond-ary winding' 22|- of moto1- 223-. The main winding of the motor 22D is connected', to the constant source of alternating current by conductors 224-'- and 225,- the phasing between these voltages-issuch that the motor angularly positions the throttle in such a direction that the resulting increase or decrease in the manifold pressure turns the rotor winding 2li toward'y the A nullposition to agreev with the pressure change.

say eighty per cent, then a further call for anY increase vin the intake manifold pressure through operation of rotor-Winding. 21| will causeoperation of a supercharger as will bei-explained.`

8 Operation of# thesuperchargerwi-lt causey the intake manifold pressure to be increased. and as, a result thepressure member 265,.,wil1 again apply voltage to the throttle actuator motor 22D to return the throttle valveto theeighty per cent reference position-.-

SUPERQHA-RGER QQNTROLy In the event the throttle valvev hasbeen Opened to the pr'edeterminedv degreeof eighty per cent upon" a further call for increase, in, theA inf-alie manifold, pressureV the further opening 0f the throttle valve willy effect operation of' an auxiliary supercharger,

The auxiliary supercharger may be drivenby suitable driving means such as a turbine driven by the exhaustggas, from the engine and applied through an. exhaust conduit. The auxiliary supercharger has an air inlet conduit, whichmay be connectedH to an aii` scoop inA a conventional manner.

There is further provided an air conduit leading from thev outlet ofthe auxiliarysupercharger to theinlet of'a main supercharger driven by they crank shaft of the engine. The speed of rotation of the superoharger and the turbine .controlled by a Waste gate ina manner well known inthe art. Any other suitable driving means for the` supercharger maybe provided'instead of' the turbine such as an auxiliary'variable speedmotor' means of any suitable type. In the instant'ca'se the waste gate is controlledv by a motor 310" through a rodv 3H: The motor 3|0` being connested to the rod 31| by a shaftv 3| 2', train of gears Sli, and shaft 315 connected to an arm 32|) to which the rod 3|| is operably connected. Motor- Sli il is of `a-reversible two-phase type, such aspreviously described `having a secondarywind'-1 ing 32| and a, primarywinding 322;. Operation of the motor 3| 0 isV controlled bythe transformer 233 having rotor winding 23|' and stator wind' ings 22, 293 and 204, as previously explained.

A- conductor 330` leadsfrom the stator winding 202 through conductor 81A to a stator winding 33| of trans-formerV 33,5; The transformer 335' has stator windings 33|, 33 1 and 338, the stator winding 33| isconnected to the stator winding 331' and byelectricaloonductor 3fm-*through anA acceleration over-speed responsive device, as` dis,- closed in the said copending application Serial No. 561,083,v tothe input of an amplifier 350; of similar type to amplifiers ||'|lv and 2|5L Conductor 35| leads from ther stator winding 2M of the transformer 200tothe input of the ampli-ner 35B. A rotor winding 33Gofthe trans,- former 335 is connected-- by conductors 360 and 33| tothe conductors 63' and 64 leading from the main source of alternating current.

The rotor '25| isso 'arranged in relation to the stator windings 2-2-and 29d-of' theV transformer EQif'that upon--the'throttle-being positioned by the motor 22B-toa position lessr than a predetermined-null position' of', for: example, eighty per' cent open, a combined voltage willV be, induced into the windings 2G21 and 2044 which will be opposed tothe, combined voltage induced-into the windings 33| and 331 by the alternating current in the transformer 335,. The differencebetween such combined voltageswill cause a flow` of current tothe input of the amplifier 35ll'and through output' conductors 3.62,-- and; 36.3.- to;v the secondary winding 32|. The-saidcuirent in; the

winding 32| having sucha, phase relationship with the alternating current -wingm the-main winding 322 as to tend to rotate the motor 3|0 in a direction opening the waste gate 305.

In the initial adjustment of the throttle Valve from a closed position, the waste gate will be held in an open position by this action of the motor 3i@ until the null point of the throttle valve of say eighty per cent open has been passed.

When the throttle 3 has been adjusted to a position in excess of the null point, the cornn bined voltage induced in the windings 33| and 331 and that induced in the windings 202 and 204 by the alternating current in the winding 20| will have an opposite difference. Such predominating voltage will cause a iiow of current to the input of the amplier and to the secondary winding 32| opposite to that previously described and the current flowing in the secondary winding 32| will be of a phase sufficient to initiate operation of the motor H0 in a direction for closing the waste gate.

`|There is also anixed to the shaft 320 a cam 330 on the cam surface of which rides a cam follower arm 38| which adjusts through a shaft 332, the rotor winding 33S of the transformer 335. The cam surface of the cam 380 is such that the cam 380 adjusts the rotor winding 33S only within an initial closing range and an extreme closing range of the waste gate 305. The winding 335 thus provides within these limited ranges a follow-up responsive to the position of the throttle valve whereby there is induced into the stator winding 33| and 331 a voltage which will be equal to the voltage induced in the stator windings 202 and 234 by the rotor winding 20| at corresponding positions of the rotor windings.

Between these two extreme ranges, control of the speed of the supercharger will be controlled by the position of the throttle valve to one side or the other of the null point in response to the operation of the pressure responsive member 265 controlling the transformer 259. Thus between the two eXtreme ranges there is a range wherein control of the supercharger 300 is effected in response to the intake manifold pressure.

It will be readily seen that as the waste gate is closed the speed of the turbine will be increased and the supercharger will be driven by the tur bine at an increased speed. An increase in the driving speed of the supercharger will eifect an increase in the pressure supplied to the intake manifold which will cause the bellows 255 to further contract moving the rotor winding 21| into a position calling for less pressure and effecting through windings 201 and 208 of the induction switch 20S, amplifier 2|5 and motor 220 movement of the throttle in a closing direction which will move the winding 20| toward the null position. When the throttle valve has reached this null point the combined voltages induced into the windings 33| and 331 will neu tralize stopping the further opening of the waste gate 365.

Should the pressure within the intake manifold increase for any reason the bellows 255 will contract moving the rotor winding 21| in a direction calling for less pressure, whereupon the motor 22S will actuate the throttle 3 in a closing direction and causing a difference in the combined voltages induced in the windings 202 and 2st through the winding Zill, and the combined voltages induced in the winding 33| and 331 by the alternating current in the rotor winding 33t.I

This difference in voltage will effect the winding 32| of the motor 3|!) through the amplier 350 in such a manner as to cause the motor 3|0 to rotate in a reverse direction tending to open the waste gate whereupon the turbine will be given by the exhaust gas from the engine 4 at a slower rate effecting a decrease in the intake manifold pressure to the selected value.

From the foregoing it will be readily seen that there is provided novel means operable through power control lever for rst positioning the throttle valve in accordance with a selected intake manifold pressure, and further novel means for increasing this intake manifold pressure upon the throttle being positioned in excess of a null point including novel means whereby the speed of the supercharger may be regulated in accordance with the intake manifold pressure so as to maintain the pressure selected through operation of the ypower control lever The selection of the intake manifold pressure may be Varied as desired within the range of the system.

OVERSPEED RESPONSIVE CONTROL CIRCUIT Stabilization of the waste gate actuator or supercharger speed control means motor 3|0 is specifically provided by a control system 400 including an alternating current generator 40| driven by a shaft 402 from the supercharger turbine shaft 30B as shown and described in the said copending application Serial No. 561,083.

OPERATION In operation, when the pilot through lever moves rotor 11 according to a selected position, there is induced a certain combination of voltages in the stator windings 18, 19 and 80. These voltages are applied to the measuring follow-up transformers, for example, the follow-up transformer 259 in the manifold pressure control to thereby cause currents which produce a resultant eld in its stator windings 260, 26| and 262.

If the position of rotor 21| of this follow-up transformer, determined by the manifold pressure acting on diaphragm 265, is such that the voltage induced in the follow-up rotor 21| is zero no control operation will be effected. If the rotor 21| is not in this position, as when the measured manifold pressure differs from the pilots selection, there will be induced a voltage in the followup rotor winding 21| the phase of which is determined by the direction of coupling.

The voltage from single phase rotor 21| is then applied through conductors 282 and 283 to stator winding 201 of switch 20S. This induces a corresponding voltage in rotor 208, which is carried by conductors 2|0 and 2|| to the amplier 2|5, the output of which amplier feeds the secondary phase winding 22| of the two-phase throttle actuator 220. The other phase winding 222 of this motor 220 is connected to the main source of alternating current.

The phasing between these voltages in the motor windings is such that the motor 220 actuates the throttle through gear trains 24| and 244i, and in such a direction that the resulting change in pressure causes the diaphragm 265 to actuate transformer 21| toward the null position.

The same principle of operation applies to the governor actuator, which includes a follow-up transformer 33 positioned by a two-phase motor connected to the output of amplifier H0 which operates as a direct follow-up from the pilots control lever and the transmitter 11.

y This transformer 93 is electrically connected to .the 4.pilots transmitter 'H in parallel with the .manifold pressure .transmitter 259, .and A.if the position `it measures differs .from that .sleected, it feeds a signal Vto the .input of amplifier H0 .by `conductors |00 and .10| from its single phaserotor 94. The output lof amplifier H0 leads to the secondary winding H3 of .the two-phasefgovernor Vactuator motor H4 to adjust the -pitch of the .propeller Mil. The pitch of the lpropeller |4B..be .ing decreased as the selected manifold .pressure is increased by movement of the .control lever in .aclockwise direction.

In .addition -to the two-phase throttle actuator motor .225! .there is lprovided the .transformer 201) with rotor .20.1 and .stator windings .-202, l203 .and 284. When the transformerZO is used vas Ia .follow-up .at small throttle openings, the 4voltage induced across the .stator .windings `202 and 203 thereof is=compared with thatinduced across the stator windings '1.9 and 80 -of the transmitter 16.

The difference between these voltages .is .fed -to stato).` winding 265 of induction switch 205, which through induction to 'rotor 268 isfed by conductors 2|| and ZIB to amplifier 2|5, and its output is fedlby conductors I2`||5 yand 2 I?! -to it-hesecondary winding 22| of the twophase -motor 2120 to=cause actuation thereof in rthe proper direction -to position the throttle.

Whether the throttle actuator '220 is actuated as a ,direct follow-up from its `connection with transmitter 16, -or is actuated from connection with the pressure .follow-.up transformer 259 is determined automatically 'by cam 250 driven by the :throttle actuator `motor 22 0 'through'shaft y242, so as 'to control the position of the rotor 208 .of inductance switch 2GB. The .ca-m 25Bis so shaped and so proportioned as to transfer from the direct follow-up connection with the transmitter 16 to a follow-up connection with the engine manifold pressure control follow-.up transformer 259at approximately v 35 per cent open.

The transmitter 1G causes 4a direct follow-up adjustment of the throttle `frorrrzero to approximately thirty per cent-open position and provides manualh1 operable means .for .overcoming the effects which :would otherwise be produced by .controlling -the fthrottle valve through the .intake manifold pressure `in view of the 'characteristic inversionof pressure at the intakemanifold of an engine `which occurs upon adjustment .of 4the throttle valve to lsomewhat less than Vthirty per cent open. Moreover the latter manually operable means facilitates the starting of .the engine.

Thus'when moving the pilotis .control'lever 'l in the range corresponding to the'zero to vthirty per cent throttle zvalve .open position, vproportional opening of the throttle valve is accomplished and the throttle Valve `followsthe positionof .the .control lever When the throttle valve is :in aposition'aboye thirty-'five .per .cent open, the .throttle valve .is vin pressure follow-up, that is, thesame is positioned in accordance lwith vthe intake :manifold pressure selected by the .f .iilots'control lever Vhen the throttle valve yis between thirty iper cent and thirty-five per ,cent fopen the signal pto the amplifier 215 .is 'a icombinaticn iof position follow-up and pressure follow-up. The reason for the latter arrangement is to provide-a smooth transition from the-position follow-up to thefpressure follow-up.

With reference to the throttle actuator motor 22o fthe rotor winding 20| of the rotary trans-- former 206 is arranged to induce a voltage .in the statorwindings t2 E12 .and 204 which are .in-turn :connected .to the `stator windings .331| V.and .3.3.1 of the transformer 335. The .rotor winding .-336 of Vthe transformer 335 ,is arranged to induce an opposing .voltage in the latter stator windings .33| and 331. The vdifference between the said-opposing voltages determines thedirection of rotation .of the .motor -3|ii. The said rotor .windings 20| and 33t being so arranged that when the throttle valve is .positioned below a predetermined null point of -say .abouteighty per cent-open the motor 3||l --will be actuated in a direction for opening the wastegate 365 so yas :to .decrease the speedfof the .supercharger 30D. Conversely, Awhen :the throttle valve is in a 4,position vmore .than the said null position of .about eighty ,per `cent open .the .motor 0 will -bedriven in a direction for=closing the .wastegate so as to increase `the driving speed of .the ,auxiliary supercharger and thereby the pressure within the .intake manifold. Such loperation .thus regulates the boost pressure from the supercharger so that selected pressure can .be maintained. However, upon .the rotor winding .2m .being returned to the null position due -to the ,operation .of the `manifold pressure responsive means .2135 vand 259, operation 'of the Amotor-3|!) will cease.

During operation, .it being remembered that the .pressure follow-,up vtransformer 259is in ,control, .if the pressure :selected by .the pilot through movement of the transmitter FIG issuch that .the throttle moves ,to more .thanthenull position-or about .eightyper cent of the .wide open position, the throttle transformer 2-09 .causes .a signal .voltage to be transmitted to thelamplier 350, vwhich in turn operates .the two-.phase waste-gate motor 3 `toelose the Waste gate .and increase .the turbinespeed. This .will cause an Iincrease in supercharger output, .and therefore an increase .in manifold pressure. This pressure .operates through .a manifold pressure responsive element 265 .and it is connected .to follow-up transformer l259 so .as to cause the ,throttle to .close slightly, until about eighty per cent .open ythrottle .position or the null .position is reached. .At this position, the .transformer 20D .in the .throttle .actuator .and the transformer 335 induce neutralized signals to the follow-up motor 34.0.

,Should the .pilot .now `select `a different pressure by moving the transmitter rotor 716, the measured manifold pressure and selected pressure will differ, and .the Vthrottle will then .be moved to produce the desired value. Since the .throttle actuator transformer .255 has moved from the null position, or from about .eighty vpercent open throttle position, it causes a signal to be transmitted to .the waste gate actuator follow-up motor 3|!) to change .its setting. Again the resulting changein-manifold pressure will reset the `throttle toits null .or abouteighty per cent open reference position.-

.If .the .selected pressure such that the throttle is heldin .a position .less .than .the null position, the system will hold the waste gate wide open. On the other hand, if a high pressure is selected, so that the `turbine 3|i| is operating at top speed as ,limited by the overspeed control. network 40|), the throttle will be opened more than the null position to produce the selected pressure, or as near this pressure Aas can be produced with top speed of Athe turbine V351| and wide open throttle.

If theiconditions are such that the turbine 30| is operating at any speed between its minimum (as determined with .the waste vgate wide .open) and itsmaximum Las Vlimited bythe overspeed control of the circuit Mill), .the throttle will always be at the null position or about eighty per cent open, except during transients. The purpose of using this reference position, instead of waiting until the throttle valve is wide open before increasing the speed of the turbine is to have a means of immediately providing any required change in pressure without waiting for the turbine to accelerate and also allow for the time delay required for the air to flow to the engine. Without this feature, a selection of higher pressure for more power Without moving the throttle valve would require closing of the waste gate and momentary loss of engine power due to higher exhaust pressure.

Further, in order to add stability to the system, a rate circuit is provided in the circuit B for preventing acceleration or deceleration of the supercharger in excess of a controlled limit, as disclosed in the said copending application Serial No. 561,083.

In case of failure of the system or the main alternating current supply, a combined electromagnetic and mechanical clutch is provided between the automatic throttle actuator means and the throttle valve, so that when power is on, the electromagnetic clutch is connected to the automatic throttle actuator means. Ii the power is turned off, the clutch 2 shifts the connection of the throttle from the automatic throttle actuator means to a mechanical connection for manual operation by lever I through clutch 2. When the power is turned off, a suitable spring, may be provided which will open the waste gate, and the propeller pitch governor will remain at the setting in which it happened to be at the time that the power was turned olf.

NOVEL FEATURES Supplemental fluid injection control The present application relates to novel irnprovements in the aforenoted system of application Serial No. 561,083 and shown herein in Fig. ure 1. These novel features are shown diagrammatically in Figures 2, 3, e and 5 in which like numerals indicate corresponding parts.

Referring to Figure 2, there is indicated by the numeral 50i a solenoid arranged to operate an armature 503 biased downwardly by a spring 505. The armature 553 operates an adjustable stop 501 pivoted at 509 so as to limit the adjustment of the main control lever l upon de-energization of the solenoid 59H, while permitting a higher pressure setting by the control lever l upon energize.- tion of the solenoid 553i. The solenoid 50| is electrically operated in conjunction with the usual supplemental or anti-knock fluid injection control of the engine which may be of a type shown in U. s. Patent No. 2,453,653 granted November 9, 1948, to Howard A. Alexanderson and assigned to Bendix Aviation Corporation. The supplemental uid injection control is shown in Figure 2 as including a control valve 5l! provided in a conduit 5G31 for the supplemental fluid and connected between a fluid supply pump and fluid metering device not shown. The 'valve 5l i is arranged for off and on control of the supplemental iiuid injection system. The valve 5I i is shown herein as of an electromagnet controlled type having an electrical control circuit 55 including a source of electrical energy Ehi,

the solenoid 50i, and a switch 5H which is preferably mounted within the aircraft cabin for convenient operation by the pilot. Thus the supplemental fluid injection system may be placed irroperation by the pilot closing the switch l'i so 14 as to effect the opening of the valve 5H which would simultaneously eiect energization of the solenoid 50| permitting the pilot to increase the selected intake manifold pressure. Conversely the valve 5| I may be closed by opening the switch 5 I 'I so as to shut off the supplemental uid injection system and de-energizing the solenoid 5B1 so that the spring 505 will actuate the stop 501 in a system is used, the manifold pressure vs. R. P. M.

schedule is extended to include operation of the supplemental fluid or water injection system.

Waste gate control A further feature of the present invention over that disclosed by (Figure 1 is illustrated in Figure 3 and claimed in copending divisional application Serial No. 110,819, iiled August 1'7, 1949, and assigned to the assignee of the present application. In the improved system of Figure 3, the cam 380A is substituted for the cam 380 of Figure 1. In the latter arrangement, the throttle valve follow-np transformer 200, the waste gate followup transformer 335 and the cam 330A are so designed and adjusted that the waste gate will remain open for a substantial part of the throttle rotation from the closed position to, for example, a sixty per cent open position, the waste gate will then be closed by the motor 3| il in proportion to the throttle valve position as the throttle valve is further opened until at a full open throttle valve position the waste gate will also be adjusted to a fully closed position.

It will be seen from the foregoing that the A. C. voltage from the throttle valve follow-up translformer 200 is the signal which controls the waste gate position. The transformer 200 in the latter arrangement is so set that when the throttle valve is fully closed the difference between the combined voltages inducted by transformers 200 and 335 is of such a phase that, when amplified and applied to the waste gate actuator motor 3 l 0, it will cause the motor to fully open the waste gate. As the throttle valve is opened this voltage falls to a minimum at a predetermined intermediate position of, for example, sixty per cent open throttle valve position, and then increase again substantially at degrees out of phase as the throttle valve is opened past this intermediate position. This voltage when amplified and applied to the waste gate actuator motor 3W is then of such a phase as to cause the motor 3|!! to close the waste gate. Voltage from the resulting adjustment of the waste gate follow-up transformer 335 then counterbalances the voltage from the throttle valve follow-up transformer 200 so that the position of the waste gate in a closing direction follows the position of the throttle valve in an opening direction past the intermediate position. The rotor 336 of the waste gate follow-up transformer 335 is driven by the cam 380A secured to the actuator output shaft 320, and a cam follower 3B! secured to the shaft 382 of the rotor 335.

The cam 380A is so shaped that upon adjustment of the waste gate in a closing direction in response to' a signal voltage resulting upon a encarta further .closing movement nf the throttle valve the cam .360A eiects a flolloweup adjustment of Multi-.engine control There is lfurther provided a novel single lever control for multi-engine operation. .In lthe said application Serial No. 561,083, separate control levers were provided for the control system of each engine.

However, .as shown in Figure 4 and disclosed and claimed in the said copending `divisional application Serial No. 110,819, there may be provided a novel single .lever `control for the .control systems ,of two .or more engines supplying balanced power to an aircraft and there .may be ifurther provided vnovel means for selectively varying the power appliedat .one side or the other of the 'aircraft .by such engines.

During take-off, the .natural tendency is for a balanced power multi-engine aircraft to veer or turn from a xed course due vto engine torque or the direction of rotation of .the propeller blades. In order to steer the airplane in a lixed .direction under -such conditions, .the engine power at one side of the plane may be reduced so as to balance the tendency of the .plane to Veer. This expedient may also be .used to overcome .the tendency of cross winds to change the direction of the craft.

Referring to the drawing .of Figure 4, there is illustrated -diagrammatically .the subject single lever control for a multi-engine aircraft. The control includes .a shaft 550 .to which may be Vimparted rotary motion to operate the master transmitter 16 which may include a standard 1'0- tor winding Ti .inductively coupled to separate stator windings 18, 19 and '80 for each engine control system. As an -alternate means, separate transmitters for each engine control system may be provided in which the .rotors .7J of the vrespective transmitters aremechanically .connected for rotation by the-single control shaft 55.0 or .as a .further alternate arrangement a lsingle .master transmitter may be provided with theseveral receiver systems shown in .Figures .1 and 3 connected in parallel thereto. As shown .inFigure 4 the respective stator windings 18, 'I9 .and 30 .are so arranged that maximum .coupling between the rotor 'I1 :and each stator winding .occurs at the same angularposition of .the rotor TI. Thus during normal operation, therespective .engines controlled bythe system provide balanced power to the aircraft at opposite sides thereof.

There is further provided in the line 2li vof each of the engine control systems .a winding 552 to which there may be inductively coupled a winding 554 connected across lines 63 and 64 of the main source of alternating current. The windings 554 are normally positioned at right angles to the windings 552, as indicatedin Figure 4, and out of inductive relation with the winding 552.

However, upon axial .movement of the control shaft A550 from the balanced Aposition shown .in Figure 4, one or the .other of :the windings 554 will be actuated through .a lever 556 pivoted at 558'and bearing .at `one .end .upon a collar 5.60

16 formed .on the .shaft .550. Aspring :562 basesithe' lever .556 'into contacting :relation 'with the collar 555, While a stop 564 limits the movement ofthe lever 55.6 toward the collar .560,

The opposite end :of the lever 555 is linked at 556 to an arm 56B whereby rotary movement .may be imparted to the rotaryr winding 554.

It will be :seen from the foregoing that there is provided a mechanical arrangement whereby the rotor windings '5.55 may .alternately lbe rctated through an angle. The windings 554 are so set that null or zero coupling .exists between rotor winding 555 and stator winding 522 in the normal balanced position shown. .Moreover upon axial movement vof the .shaft 558 from the null position rotation of :one of the windings 554 is eiected into coupling .relation with the winding 552. r-Ihe alternating 'voltage induced into the winding 552 is -of such a phase as to cause upon amplification rotation of the actuator motor 22!! in a vthrottle valve Aclosing direction 'and thereby decrease the intake manifold pressure setting of the engine `at v'one `side -of the aircraft without eiecting ythe intake manifold pressure setting of the engine a-t the opposite side Aof the aircraft, since the other lever 55E is held from rotation by its stop `564. vHowever 1axial.niovement of `the shaft 555 in an opposite direction from Vthe -null position will similarly move the .other rotor Winding 551i from its null position .so as to decrease the intake manifold pressure setting of -the engine at the other side of the aircraft, without effecting .the null position of the first mentioned rotor winding'55. Thus .there is provideda novel intermittent drive `whereby the intake lmanifold pressure in the engine .or .engines .at one .side of an aircraft may be reduced without effecting an increase in the intake manifold pressure setting of the -engine `or engines at the opposite side of the aircraft.

-The stops 564 may be eliminated so that the intake manifold pressure of the engine or engines at one side of the aircraft is reduced while the intake manifold pressure of the engine or engines at the other side of the aircraft is increased upon axial movement of control shaft 556 to one side of the null 'position'and thereby eiecting unbalanced power to control the direction of the aircraft.

In the event there are provided more than one engine at opposite sides of the aircraft, each of the rotor windings 55:1 may be inductively coupled to stator windings corresponding to `windings 552 in the control systems of the respective engines at one side of the aircraft so as to permit the power applied by the multi-engines to be unbalanced in like manner at the will of the operator through manipulation of the single power control shaft 556.

As a further alternate form of the invention,

the main control lever, as shown in Figure '5, may

be oi the type shown in'Figure l 4and indicatedl by the numeral with the addition of a manually operable ball 57D mounted on the 'lever l and driving through a shaft 512 a pinion 514 engaging a rack 515 to impart axial movement to shaft 556 as described with reference to Figure 4. The lever I may be rotated with a shaft 585 in a suitable bearing. The shaft 58B is arranged concentric With the shaft 550 .and there is slidably mounted vin shaft 53S the rack 5?'6. Thus the lever .may be manually operated to position through rod lll, the rotor .1.1 .of the transmitter 's' for the respective Iengine control systems, as 1clescribed and y.claimed in the said .-copending :intif-` 17 sional application Serial No. 110,819. As disclosed and claimed in the present application, the lever I may be further limited by the stop 501 in response to the condition of the supplemental fluid injection system as heretofore described with reference to Figure 2.

It will be seen from the foregoing that any one or all of the foregoing improvements of Figures 2 4 and 5 may be applied to the basic system of Figure 1 and which basic system has been heretofore described and claimed in the said copending application Serial No. 561,083.

Although only three embodiments of the invention have been illustrated and described, various changes in the form and relative arrangements of the parts may be made to suit requirements.

What is claimed is:

1. For use with an induction system of a supercharged aircraft engine having operable means for injecting a supplemental fluid for suppressing predetonation of said engine; the combination comprising means for regulating said induction system so as to maintain the pressure thereof at a predetermined value, manually operable means, other means operated by said last mentioned means to select said pressure value, stop means limiting the range of adjustment of said manually operable means in a pressure increasing sense, and electrically operated means responsive to initiation of operation of said fluid injection means to affect said stop means so as to increase the range of pressure selection by said manually operable means.

2. For use with an induction system of a supercharged aircraft engine having operable means for injecting a supplemental uid for suppressing predetonation of said engine; the combination comprising means for regulating said induction system so as to maintain the pressure thereof at a predetermined value, manually operable means to select said pressure value, stop means limiting the range of adjustment of said manually operable means in a pressure increasing sense, means responsive to initiation of operation of said fluid injection means to affect said stop means so as to increase the range of pressure selection by said manually operable means, and in which said stop means includes a lever, spring means to actuate said lever into a limiting position relative to the manually operable means and a solenoid to actuate said lever out of said limiting position.

3. For use with an induction system of a supercharged aircraft engine having operable means for injecting a supplemental fluid for suppressing predetonation of said engine; the combination comprising means for regulating said induction system so as to maintain the pressure thereof at a predetermined value, manually operable means to select said pressure value, stop means limiting the range of adjustment of said manually operable means in a pressure increasing sense, means responsive to initiation of operation of said fluid injection means to affect said stop means so as to increase the range of pressure selection by said manually operable means, and in which said manually operable means includes a lever operable by the pilot of the aircraft, said stop means includes a second lever, and a spring to actuate said second lever into a limiting relation with said pilot operated lever, and said operation responsive means includes a solenoid to actuate said lever out of said limiting relation in response to the initiation of f 18 operation of said supplemental fluid injection means.

4. For use with an induction system of a supercharged aircraft engine having operable means lfor injecting a supplemental fluid for suppressing predetonation of said engine; the combination comprising means for regulating said induction system so as to maintain the pressure thereof at a predetermined value, manually operable means to select said pressure value, stop means limiting the range of adjustment of said manually operable means in a pressure increasing sense, means responsive to initiation of operation of said iiuid injection means to alfect said stop means so as to increase the range of pressure selection by said manually operable means, and including a solenoid responsive to initiation of operation of the supplemental fluid injection means for` actuating the stop means out of limiting relation with said manually operable means to permit an increase in the selected pressure value during operation of the supplemental fluid injection means, and spring means to actuate said stop means and thereby said manually operable means in a pressure decreasing direction upon cessation of operation of the supplemental fluid injection means 5. For use with an aircraft having engines mounted at opposite sides thereof to normally supply a balance of power, each of said engines having operable means for injecting a supplemental uid for suppressing predetonation of said engines, and each of said engines having a throttle valve to control the intake manifold pressure therefor; the combination comprising an actuator motor for each engine throttle, an intake manifold pressure responsive control for each actuator motor to maintain the intake manifold pressure of its associated engine at a preselected value, a manually operable pilots control member, means operatively connected to said member to select said pressure upon adjustment of said member, stop means limiting adjustment of said pilots control member in a pressure increasing direction, means responsive to initiation of operation of said uid injection means to release said stop means and increase the range of pressure selection.

6. For use with an aircraft having engines mounted at opposite sides thereof to normally supply a balance of power, each of said engines having operable means for injecting a supplemental fluid for suppressing predetonation of said engines, and each of said engines having a throttle valve to control the intake manifold pressure therefor; the combination comprising an actuator motor for each engine throttle, an intake manifold pressure responsive control for each actuator motor to maintain the intake manifold pressure of its associated engine at a preselected value, a manually operable member including means to select said pressure upon rotation of said member, stop means limiting the rotary adjustment of said member in a pressure increasing direction, means responsive to initiation of operation of said iiuid injection means to release said stop means and increase the range of pressure selection, in which said means to release the stop means includes a solenoid responsive to initiation of operation of the supplemental uid injection means for actuating the stop means out of limiting relation with said manually operable member to permit an increase in the selected pressure value during operation of the supplemental iiuid injection means, and

thereby said manually operable membler-fiin-a pressure, decreasing direction yupon ycessation of 9999411011 0f Ithe .supplementalflilid Linietion :'ffior 11S@ with an. nductionsystem-ia Supercharged taircraft engine lhavingoperable means io'rfinjectinggf a supplemental uid for. suppressfing'predetonation ,of` s'adjengirie; 'the combinafionlcbmijris'ingmotor means for regulatingthe induction pres'sureof V'said engine,V an induction Sure responsive 'control for said motol-.mans maintain; tne-indut'ionpressure ofrthe engine preselected ,v1alue aliina'nually operable pilots rol'. m'emb`er,' means operatively .connected tosadinnber; to select said pressure: upon adgui'ertitIofQsail/niernber, stop. means klintirig 943199118121 0f fsm' P11995 control .memberfina .pressure ,n 'mrfasmerrfetionf l means :responsive --nLLEN- NV.I BLANCHARD.

A,I eferences,Cited in the file of this patent UNITEDLSTATES :PATENTS Y Number `Name Date 1,784,671 AJeni@ Dec.9,1193o 2,199,259 Hersey*.r f r r. Apr.-3D, 1940 :2,381,429 Bell etal. T-- Augj?, 1945 2,464,636 Eaton??V Mar.'1v5, 1949 V2,491,482 Dolza iet al v -rDec.-20, 1949 2,491,484 Dvolzaetal :Dec.20, 1949 2,491,497 Jorgensen et a1 Dec.2 0, 1949 

